a general of infantry in Gaul, where he completely succeeded in quelling a formidable insurrection of the barbarians during the reign of Constantius (A. D. 355), to whom he had rendered an important service upon a former occasion by deserting, with a large body of cavalry, from Magnentius, immediately before the great battle of Mursa. Having been falsely accused of treason by an informer who produced forged documents in support of the charge, he was urged by despair to commit the crime of which he had been so villanously impeached, and assumed the purple at Cologne, about the end of July A. D. 355, almost at the very moment when his innocence had been triumphantly established before the imperial tribune at Milan. Ursicinus having been despatched with a few followers to crush this rebellion as best he might, effected by treachery the destruction of Silvanus, who was murdered twentyeight days after he had been proclaimed Augustus. He is represented by a contemporary historian as an officer of great experience and skill, not less remarkable for his gentle temper and amiable manners, than for his warlike prowess. It is not improbable that he may be the Silvanus named in the Codex Theodosianus (Chron. A. D. 349) as a commander of infantry and cavalry under Constans.

(The details with regard to the unfortunate usurpation of Silvanus are given with animated minuteness by Ammianus Marcellinus, 15.5, 6, who accompanied Ursicinus upon his hazardous mission. See also Julian. Orat. i. ii.; Mamertin. Panegyr. ii.; Aurel. Vict. de Caes. 42, Epit. 42 ; Ettrop. 10.7; Zonar. 13.9.)